I've been developing peercalls.com on and off on since 2015. It's an open source peer to peer WebRTC audio/video calling service, allows the users to chat, share their desktop and send files (sending files is a little buggy at the moment, works best in Firefox).

It has gotten a lot of interest in the past month and I noticed a spike in web traffic so I'm actively working on making it more scalable. I'm planning on implementing an SFU to support calls with more than 3-4 people. Right now the peers establish a mesh network and it quickly gets expensive to send video to more users.

I've also been paying attention to the criticisms of Zoom and other WebRTC conferencing services and am hoping to implement end to end encryption for intermediate servers using Insertable Streams once the functionality is supported in most browsers.